hi just had a look at your grow looks very impressive (and expensive lol) where are you growing as 64 rh is very high for flowering plants, and all this talk of products to use for speider mites is silly, if you have mites you've done something wrong prevention is the answer not cure. Taking a few basic steps will ensure anyone can avoid mites again starting with never growing clones from anyone else, and other commen sense practices, if you want to know more let me know.
...and hot air like this will definitely bring the humidity down, if it wasn't coming from such a swampgas filled windbag!
First, 64% humidity is fine. If you want, you can bring it down 10% for final flowering- it's one more way the plants know it's time to finish their life cycle.
Second, fool has obviously never had problems with spidermites, so ignore his 'advice.' Prevention is fine but once they're in your garden it's time to deal with them, not whine about what you 'should have done.' It's really too late to spray anything on these buds without risk of damaging them. After these girls are out of the room, however, you'll need to thoroughly clean the place up. Also, make certain you're not accidentally carrying the little monsters from this room to any others with plants in them- even houseplants can be a reservoir for infestations!
Getting clones from others is not only fine, but is the only way to be certain of what you're getting. As with anything you get from outside your garden, care must be taken to prevent contamination. Therefore, keep new clones in isolation from all other plants, and spray them preventatively for powdery mildew, spidermites, etc, and let them sit that way for a week or so before placing them near your other crops.
Yes, your setup cost some money. So what? Looks like it's getting good results, especially for the limited space you have to work with. The issues you're encountering are similar to those any other grower might experience. Funny how the guy's signature said he was waiting for equipment- guess that's proof all his knowlege came from a book!
As far as checking for ripeness goes, I'd say your photography skills are fine! Bring your temps up 1-2 degrees C, and if you want, let your humidity drop 10 points, both will help encourage ripening. In general, growing hydroponically means 1-3 weeks longer growing time, which means better yield- not a bad thing, right?
Keep up the good work!